Sound producing device for signaling purposes



May 12, 1953 R. E. swANsoN SOUND PRODUCING DEVICE FOR SIGNALING PURPOSES Filed March 28, 19 50 2 Sheets-Sheet l INVENTOR PTEM/Vfd/M MM/M ATTORNEY May 12, 1953 R. E. SWANSON scum: PRODUCING DEVICE FOR SIGNALING PURPOSES 2 Sheets-Sheet 2 Filed March 28, 1950 INVENTOR 5.5?7'5 Jim/$0M MM MQM ATTORNEY Patented May 12, 1953 UNITED STATES ATENT OFFICE SOUND PRODUCING DEVICE FOR SIGNALING PURPOSES New York Application March 28, 1950, Serial No. 152,333

16 Claims. 1

This invention relates to improvements in a sound producing device for signalling purposes and particularly to pneumatic horns used on railway locomotives.

As usually constructed pneumatic horns of the multiple type point in one direction, namely to the front of the locomotive and, as most horns are inherently directional in their sound propagational qualities, it can be expected that horns will be more efiective in the direction toward which they are pointing. In railroad signalling it is often desirable to have the sound of the horn carried far to the rear of the train to call flagmen, and when all the horns point in a forward direction their sound cannot be heard as Well to the rear. To overcome this difficulty it has become necessary to install two separate and independently operated horns on a locomotive if the sound is to be carried in both directions. With the advent of multiple air horns using several horns constructed into one unit and used for forward signalling it would be unnecessary to install another separate horn pointing in the opposite direction if units of the existing group of horns could be reversed.

It is an object of this invention to provide a multiple air horn in which horns arranged on one base for unitary operation can be reversed so as to point in either or both directions.

Another object is to provide a multiple horn that when horns are reversed the overall length of the horn unit will not be excessively long.

A further object of the invention is to provide an improved multiple horn which incorporates air diffusing plates and removable horn seats in each diaphragm casing, which parts are held in place by assembly bolts used to attach the diaphragm casings to the base and which bolts are sealed within the diaphragm chambers.

A further object of the invention is to provide an improved horn which is simple in construction and can be produced in quantities at low cost.

Other objects of the invention and features of novelty will be apparent from the following description taken in connection with the accompanying drawing in which Fig. 1 is a fragmentary horizontal sectional view of a double tone multiple horn with the horns pointing in opposite directions; dotted lines show the arrangement when both horns point in one direction;

Fig. 2 is a vertical sectional view, partly in elevation, along the plane of line 2-2 in Fig. 1;

Fig. 3 is a vertical sectional view, partly in elevation, along the plane of line 3-3 in Fig. 2, showing reversible drilling and air porting in the base to which a diaphragm casing and horn bell may be attached to point in either direction. It will be noticed the large center hole through the base casting forms a part of the horn chamber; and

Fig. 4 is a vertical sectional view, partly in elevation, along the plane of line 44 in Fig. 1.

Like characters of reference denote similar parts throughout the several views and the following specification.

Referring to Fig. 2, a substantially T-shaped base it is provided with a flange II at its central branch [2 for fastening it to a locomotive or other structure on which it is to be mounted. Side branches I3 of the base 10 terminate in cylindrically shaped ends I l, the walls of which are drilled for bolts I5. Each end 14 is provided with a central round aperture IE.

IT is a horn bell having a flange l8 which abuts a side of one of the ends M of the base In and is held there by the bolts 65. The outer end of the bell is flared at IS. The inside of the bell forms a resonant air chamber, its smallest portion being concentric with and forming a continuation of the central opening l6 through end It of the base.

20 is a diaphragm housing having a wall 2| abutting an opposite side of end [4 of the base l0 and which is held there also by bolts I5. 22 is a central opening through the wall 2| concentric with and of the same size as opening H3 in end I4 of the base. The outer portion of the diaphragm housing is enlarged to receive a cap 23 provided with a vent opening 23a and an inwardly extending annular projection 24 to clamp a flexible diaphragm 25 against a shoulder 26 within the housing. Cap 23 is fastened to the housing by screws 21. 28 are lugs on the cap and housing having holes 29 for the reception of a wire seal 30.

3! is an annular seat ring inserted into wall 2! of the housing 20, coaxial with opening 22 therein. Seat ring 3i is provided with a shoulder 32 where its outer diameter is slightly reduced. 33 is a circular diffuser plate seating against the shoulder 32 and held there by heads 36 of bolts l5 which as the drawings clearly show also connect together the diaphragm housing 20, base It, and horn bell ll. adapted to seat upon the outer face of seat ring 3|. The diameter of the diffuser plate 33 is slightly smaller than the inner diameter of the housing 20 forming an annular orifice 35 between The diaphragm 25 is' them. Diffuser plate 33 divides that part of the housing 20 between diaphragm 25 and wall 2| into an air difiusing chamber 36 and an operating pressure chamber 3? in communication with each other only by means of orifice 35. 25a is a chamber between: the outer. surface of diaphragmlh andicap 23 which is .open1toxthe atmosphere.

38 is an air port through the vertical central branch [2 of the base l connecting with a duct 39 in the horizontal side branches of the" base:

40 are cross ducts through the walls ofends- M" of the base in communicationwith.duct39s. Each. cross duct 40 has one end closedby thevflange-ilflof the horn bell ll, while; its: other. end isino communication with chamber 36 of the housing by means of a port 4i. Aincan be. admitted into the porting just described, through either of" openings 42 (shown plugged) in bossesgtdiatithe: sides of the central branch i2 above the flange H whioheveris most convenient. The. air. port 13 isblanked ofiat thebottom of/thebase by the flange ll 'contactingthe. structure uponwhich thetdeviceiismounted. Atight sealis provided for between, the. abutting surfaces; of. diaphragm 2'8; .base l B}. and .ho'rnibell H, to prevent the, escape of air by either well'rnachined' surfaces: or. gaskets.-

Ittwillf be noted thatthe inner part of'seat i'ingjl, central opening, 22" in the wall of housing; Wi. opening, 'lBl base It,v and the inside ofho'rn' hell I T 'are' aligned and forma continuous resonantwairv column terminating into the free atmosphere 'atthe fiare'dend of the belland being closedat the'other end'by diaphragm 25. Such aircolumnst with respect to resonance are governed by the natural laws which govern stopped organ'pipes and areone-quarter wave length of theirfunctional frequencies; the overtone harinonics being thirds, fifths and'sevenths. These resonant air columns are'oi different lengths calcul'atedto produce'harmonious soundswhen both horns are soundedtogether -as outlined later;

It istnotthe purpose of this invention to limit the assembly off horns in one unit to any par?- ticular'number; any numberof hornsoi" different frequenciesr'in relation with each other may" be attached to sucha=-mult'iplebase as herein explainedor a single horn may be attached inthe manner: When'for instance; three. horns F are. attached they'may be constructed: with suite a'ble" horn" bells and" diaphragms to produce a chord in a m'aj or key and? if" it is desirable to change the key to a" minor'chord' differenthom bells'and"diaphragms'maybe substituted as. all-parts can be. interchangeable with each dth'erhy this novel. means .of attachment.

Referring turn; 1, it will" be noticed'cap 23 is attached" to. diaphragm housingjil; holding diaphragmfiin .place by screws ET. This attach- 60 mentcaniaiso-b'e accomplished by threading cap 23%into housing-2e; howevena; seal attis provided through lugs. 28 which prevents the removal of cap 23"'*1inless:seai..?f6' is broken. By thismea'ns, the heads-offibolts i5 are also sealedso thatthe homc'annotbe tampered with orits directionrevc'rsedunless" theseal'is broken.

Referring again to Fig. 1} as well. as. Fig.3, if "it" becomes 1 desirable to a reverse. the. direction era lioi'n leaving" the other horn (or horns) pointinginaziorward'ldirection, it isronlyv necessary; to break the seal 30,- remove. screws 2'] lift outidiapliragm' ;.aiterwhichbolts Iii are re moved, allowing" housingili' and h'ornibell IT. to bbdet'achedfiomend'. l 4' of the. base. i 0. Housing 20 is then interchanged with horn bell I! so that housing 20 is on the right side and horn hell I! on the left side after which bolts l5 are again tightened up. The horn is then in the position shown in Fig. 3.

Referring again to Fig; 1-,'it=w-ill-be. noticed that seat-iiringi-"kl is held in. position by pressure exerted on diffuser plate 33 by bolts l5 when tightened against shoulder 32 of the ring. This is an advantage and an improvement over other horns inthat'the seat bushing is held rigid and can" be renewed in the field Without resort to speciaLtools.

Itwill. also. be-noticed that with the novel arrangementofv assembly by using a portion of the base ID; to form a chamber It as a central portionof the horn bell II when a horn and diaphragm" casingarereversed the overall length of theentire: multiple horn unit is not doubled in length as would be the case if the housing 20 and cap. 23,1011. instanca. were, integral partsv on the base ['0' and used'to. mountand supportthe horns, which latter system of. mounting horns to point in one direction is well'knowninthe. art...

Operation:

Referring to Figs: 1 and 2,. air under pressure enters" the" manifold" base ID from? a" source of pressure supply" and news through" one of the openings 42 into air, port 38 where'it enters "duct 3B-"c'o'nnecting withcross ducts 40. The air: then fiows through restricted:ports:llinto chambers 3b" where it" impinges: against" 'difius'er" plates 3 3' breaking its-velocity and building up a pressure in chambersfli so that air. enters chambers 31 through thin annular orifi ces Pressure in chambers 3'1then'bui1ds up to a higher'pressu're than exists iii-chambers ZBwwhihare connected to the" atmosphere through vents-13a; As. the pressur incha'mbers- 3T-corrtinuesto buildup the diaphragms' Hare-deflected intothe chambers 25a displacing the'air in chambers 25a to" the atmosphere. When this *occurs a-circular' puffof airis admitted into resonant .air'chambersi-formed by seatiring 31-; basel0 and horn bellllj suddenly releasing thepressure from? chambers- 3! and as diaphragins-v 2'5 are-thin circular leaves-of a spring-like nature calculatedto-vibrate=on the natural frequencies or third, fifth andseventh harmonics of 'tliese' air chambers: vibration is'set up in the 'diaphra'gms zei which *vibration is supported andstrengthenedby the resonance-inthe air chambers of th'e' horns; which is transmitted to the atmosphere through amplifying fiares l9 resulting ina; very strong and powerful signal with: a-.. pleasing time: As: the velocity of air isincreased 'undue turbulence is avoided in cha'mbers ill-due to the air entering through thethin annular: orifice 3 5 where oil and dirt-'tis-deposited' as f arvaway as possiblefrom th'el seatingsur-fa'ce oniseatf ring 3:]: and at the same time the direct impingement efiectlofiair entering 'througlrport's 4'1: and striking the diaphragm -25 is avoided, which impingement efiect would have a tendency to distort; the: diaphragmszZS at high"pressures with: resultant: high; air velocities causing the from :thescope-of: thez'fotlowingclaimss What I claim as new is:

1. In a sound producing device, a base, a diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the base having a bore in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the diaphragm unit and the horn bell being interchangeable. 2. In a sound roducing device, a base, a diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the base having a bore in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the diaphragm unit and the horn bell being interchangeable, the base having ports for admitting fluid under pressure to the diaphragm unit irrespective of the position of the diaphragm unit on the base.

3. In a sound producing device, a base, a diaphragm unit mounted at one side of the base and a horn bell mounted at the opposite side of the base, the diaphragm unit and the horn bell being interchangeable, the base having ports for admitting fluid under pressure to the diaphragm unit, irrespective of the position of the diaphragm unit on the base, including a port having One end closed by the horn and its other end in register with a passage to the diaphragm unit.

4. In a sound producing device, a base, 2. diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the base having a bore in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, and means operable from within the diaphragm unit to draw the unit, base and horn together.

5. In a sound producing device, a base, a diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the diaphragm unit and the horn bell being interchangeable, means operable from within the diaphragm unit to draw the unit, base and horn together, and a seal locking the diaphragm unit whereby operating the means is prevented unless the seal is broken.

6. In a sound producing device, a base having a stem and branches extending therefrom, a plurality of sockets in the branches, a diaphragm unit at one side of each socket and a horn bell at the opposite side of each socket, each socket having a bore in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the stem having ports for admitting fluid under pressure into a duct common to the branches and a conduit in each socket in communication with the duct having one end closed by the horn at one side of a socket and its other end in register with an opening in the diaphragm unit at the other side of the socket.

7. In a sound producing device, a diaphragm unit having a chamber, a seat ring projecting into the chamber, a flexible diaphragm mounted in the chamber and adapted to engage the projecting end face of the ring, a diffuser plate mounted over the projecting sides of the ring, the plate forming in the chamber with its peripheral edge a narrow annular orifice, the chamber having an inlet admitting fluid under pressure to that side of the plate opposite the side facing the diaphragm whereby the fluid is forced through the narrow annular orifice to operate the dia- 6 phragm and then pass to within the seat ring. and a horn bell forming a resonant air chamber in continuation of the seat ring.

8. In a sound producing device, a diaphragm unit having a chamber, a seat ring projecting into the chamber having a shoulder, a flexible diaphragm mounted in the chamber and adapted to engage the projecting end face of the ring, a diffuser plate mounted over the projecting sides of the ring and resting against its shoulder, the plate forming in the chamber with its peripheral edge a narrow annular orifice, the chamber having an inlet admitting fluid under pressure to that side of the plate opposite the side facing the diaphragm whereby the fluid is forced through the narrow annular orifice to operate the diaphragm and then pass to within the seat ring, a horn bell forming a resonant air chamber in continuation of the seat ring, and common means holding the plate against the shoulder on the seat ring and the diaphragm unit to the horn bell.

9. In a sound producing device, a base, a diaphragm unit at one side of the base having a chamber, a seat ring projecting into the chamber having a shoulder, a flexible diaphragm mounted in the chamber and adapted to engage the projecting end face of the ring, a diffuser plate mounted over the projecting sides of the ring and resting against its shoulder, the plate forming in the chamber with its peripheral edge a narrow annular orifice, the chamber having an inlet admitting fluid under pressure to that side of the plate opposite the side facing the diaphragm whereby the fluid is forced through the narrow annular orifice to operate the diaphragm and then pass to within the seat ring, a horn bell at the other side of the base and interchangeable with the diaphragm unit forming a resonant air chamber in continuation of the seat ring, and common means holding the plate against the shoulder on the seat ring and drawing the diaphragm unit, base and horn bell together.

10. In a sound producing device, a base, a diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the base having an opening in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the unit having a chamber, a seat ring projecting into the chamber, a flexible diaphragm mounted in the chamber and adapted to engage the projecting end face of the ring, a diffuser plate surrounding the projecting sides of the ring, the plate forming in the chamber with its peripheral edge a narrow annular orifice, the chamber having an inlet admitting fluid under pressure to that side of the plate opposite the side facing the diaphragm whereby the fluid is forced through the narrow annular orifice to operate the diaphragm and then pass to within the seat ring, the inner part of the ring being a continuation of the resonant air column.

11. In a sound producing device, a base, a diaphragm unit at one side of the base and a horn bell at the opposite side of the base, the base having an opening in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the unit having a chamber, a seat ring projecting into the chamber, a flexible diaphragm mounted in the chamber and adapted to engage the projecting end face of the ring, a diffuser plate surrounding the projecting sides of the ring, the plate forming in the chamber with its peripheral edge a narrow annular orifice. the base havin ports tor admit ing i 'irrid trad orersureto the throu h an inlet t the amb to t ide of the pla e concerto the shir fleei the di p a m whereby he fluid: s f rt ism-mash th n ow nnu ar ri-fiee to oo ate he d aphra m an th n pa t Wi hin th se t in the inner pert er the e eing eeo euetien the resonant ai eo umhra o soundprod i-he device a here, a (ii-fr Phrasa unit at one, s de at he eseeh i a homehei-i-att e-opoesite sid f the beset t e beee ha iris an op ning in con nua ion o the ins de oi the em b t and io mine a eso ant olumn ther wit one en o the column b ng e se by the d oohraem uni he umtheri e eeetrine pro ectin into the e mbe he inea Should a flex ble d a hrag moimted in the ehember an adap ed t engage the PI-Qififii' ifl end ton f the r g? a d fuse Plate su unding he projecting Sides of the and r st n a ain its hcu eenthe plat orms h chamber with its p riphe al ed e a nar ow nuiar orifice, the base having ports ior admitting f u d under p ssu e to the uni rcug a inlet to me fihamberto that .side of the plate opposite u rality of sockets in the branche a iiwl mfim unit at one side of each socket one a hero boil at the opposite side of,- each socket! ecoheceket having a. bore in contmuation .0; the inside M the horn bell and harming a resonant-air eoiumc. therewith, one end or the column heme mm 7 by the diaphragm unit, the units and the horn bells being interchangeable whereby the he I bells vcan be mounted pointing inopnosite the sidefacins the d aphra m w e eby-the uid is forced through the narrow annular orifice to operate the diaphragm and then pass to within the seatr ne, th inner part f thering bein a oonti e on o he resonant air co u n, and means -ODerab e from within e d ap r m uni holding the plat a a n t the hould r 1. the se t ring and. drawing t e d aph a m u it. base nd horn b ll-t g th r t .I1I3."In a sound producing device, a base,.a diaphragm unit atone side of the base and a. horn be l t the ODpO te side .o the as he a e a me en opehine in contin a ion th inside of the r e a d f ing a reson nt air column therewith; one end or the columnbeing closed by th d ep reg nit, t n t having a ehame her, a seat ring projecting into the chamber have ins eshoul he e ible d aphra m m u ed in th ch mb r a d dapted t engag t e p oject iog end face f t e ing, a dif u e plate su roun in h pro t ng sides-of th r g and res in ag i s sh ulder the p ate forming n the chamber wi i periphe al edge a narrow annula O ifice. the ase ha ing por f r eilmit tin fluid und P es e to h un t th eueh'an inlet to th ch m e to tha sid o th pl te opposite he s ra ng he diaphragm whereb th fluid is fo ced h ugh he narrow nnul orifice to ore ate the d a ra m a d t enpee to wit n the s at ring, the inner P t of th be n a continuation o the res an column, mean operable from within the diarhraorh-un h l me he pla against the s ou oer on the s a ring an e e-W ne he-di h agm it-b se end ho n'be l g er, nd e ee lock: iiig th rnit whereby op t g the means Prevent d the seai is brok hlen -a sound produe he dev ce- .a ba e bari tions, the stem having ports for admitting fluid under pressure into a duct common to, the branches and a conduit in each sock-e12 in aom: munication with the duct having one end closed by the horn at one side vof a socket and its other end in register with-anopening in zthodiaphragm unit at the other side of the socket,

16. In a sound producing device, a base. having a-stem and branchesextending therefrom-a plurality of sockets in the'branches, a diaphragm unit at one sideof each socket and a horn hall at the opposite side of each socket, each socket having a bore in continuation of the inside of the horn bell and forming a resonant air column therewith, one end of the column being closed by the diaphragm unit, the units and the ham bells being interchangeable whereby the horn bells can be mounted pointing in opposite directions, the stem havin ports :01- admitting under pressure into a duet common to the branches and a conduit iH-Qfih socket 11150811? Number l lerhe Date L6 r --"rr "R f??? -1- rees-w A er en "Wee 20,. 1.a2r

PATENTS Nu be .Q uhtry film? 241, 50 Great Brit in "we Hair :23, 5192.5 

